The shard depicts a savage world where dragons rule, and survival demands constant violence
If you can read from your opponents that they live on self-mill, or rely on a discard outlet, there's an opportunity to make an army out of advisors and win, but otherwise, this is a good way to trigger mill if you like cards such as Deepmuck Desperado, The Water Crystal, and Zellix, Sanity Flayer
Combining this ability with the cost reduction found in artifact decks seems like a ton of fun
Creature - Shapeshifter Color tag templates(None) Enigma Thief Prowl (You may cast this spell for its prowl cost if you dealt combat damage to a player this turn with a Sphinx or Rogue.) Flying When this creature enters, for each opponent, return up to one target nonland permanent that player controls to its owner's hand
Beyond making mana, Sage can then start turning your Lands into enormous monsters
The latter, from C17, is an incredible spell for typal decks